Madder with Starch, Flour and Bran, 455 



cloth, by the second dyeing, obtained a dark very clear 

 pink colour, and the 3 lbs., by the third immersion, was 

 not half so dark. Unfortunately, it is not possible to give 

 more depth to this red by altering the proportions. The 

 cold infusion acts in this case like the husks. It prevents 

 the formation of a dark saturated colour. When the pro- 

 portion is diminished, 1 to 2 lbs. of infusion to 6 lbs. 

 madder, the red is so much darker, that one can scarce 

 distinguish whether bran alone was employed. 



In the last place, the chemical properties of this solution 

 were tested, especially the white precipitate, which a clear 

 solution of sugar of lead produces in it. This was after 

 proper edulcoration with water precipitated by hydro- 

 sulphuric acid ; the solution was clarified by heating it, 

 and, after filtration, added to the madder solution. In this 

 experiment its advantageous action on the madder-red was 

 exhibited, although in a less degree than when common 

 bran is employed. 



Although the bran prevents the formation of very dark 

 madder colours, this property, in certain circumstances, is 

 a means of lightening the power of the madder colours in a 

 considerable degree. An addition of bran causes a definite 

 quantity of madder to give out more colour than happens 

 when there is none present. This remarkable action, which 

 occurs with no other matter yet known, goes so far, that 

 solutions which already, in the usual way, are exhausted 

 to such a degree by mordanted calico, that they produce 

 only a reddish yellow colour, are rendered capable, by the 

 addition of bran, of dyeing red again. 



Article IX. 



Analyses of Books. 



I. — Philosophical Transactions of the Royal Society of London for 



1836. Part I. 



Mathematics and Physics. 



Discussion of Tide Observations made at Liverpool. By 

 J. W. Lubbock, Esq., F. R. S. 



Researches on the Tides. 4th Series. On the Empirical Laws 

 qf the Tides in the Port of Liverpool. By the Rev. W. Whewell, 

 M. A., F.R.S. 



In a previous paper, the author endeavoured to obtain the mathe- 

 matical laws of the inequalities of the tides from the results of the 



